256 THE POPULAR SCIENCE MONTHLY. 



has been often abundantly shown. Hence we should naturally expect 

 the denudation to proceed further in her case than in that of man. 

 Especially among savage and naked races we should conclude that 

 hairlessness on the body would be esteemed a beauty ; and Ave find as 

 a matter of fact that most such races have absolutely smooth and 

 glistening skins. But in Europe men often develop hair about the 

 chest and legs, though not upon the back and shoulders, while women 

 seldom or never do so. Here we see that the hair reappears in the 

 less differentiated male sex rather than in the more differentiated 

 females, with whom sexual selection has produced greater effects ; 

 while it also reappears only on those parts where the original denudat- 

 ing causes do not exert any influence. Similarly, the smooth-bodied 

 negroes, transported to America, and subjected at once to a change of 

 conditions and to circumstances which would render sexual selection 

 impossible as regards the hairlessness of the body, rapidly redevelop 

 hair upon the chest. For we must remember that sexual selection can 

 only act in this direction while a race remains wholly or mainly naked. 

 Clothing, by concealing the greater part of the skin, necessarily con- 

 fines the selective process to features, complexion, and figure. 



As to the poll, beard, whiskers of certain races, we must believe 

 that they are the result of selective preferences acting upon general 

 tendencies derived from earlier ancestors, and perhaps aided in the 

 first-mentioned instance by natural selection. The comparative defi- 

 niteness of these hairy patches, as of the callosities in the monkeys, 

 stamps them at once as of sexual origin. The poll is probably derived 

 by us from some of our anthropoid ancestors, as crests of hair fre- 

 quently appear upon the heads of the quadrumana. But as man grad- 

 ually became more erect and less forestine, as he took to haunting 

 open plains and living more in the sunlight, the existence of such a 

 natural covering, as a protection from excessive heat and light upon 

 the head, would doubtless prove of advantage to him ; and it might, 

 therefore, very possibly be preserved by natural selection. Certainly 

 it is noticeable that this thick mat of hair occurs in the part of his 

 body which the erect position most exposes to the sunlight, and is thus 

 adaptively analogous to the ridge of hair which runs along the spine 

 or top of the back in many quadrupeds, and which is not visible in 

 any quadrumanous animal that I have examined. The beard also 

 bears marks of a quadrumanous origin, as Mr. Darwin has shown ; but 

 its varying presence or absence in certain races affords us a good clew 

 to the general course of evolution in this particular. For among the 

 bearded races a fine and flowing beard is universally admired ; while 

 among the beardless races stray hairs are carefully eradicated, thus 

 displaying the same aversion to the intermediate or half-hairy state 

 which, as I suppose, has been mainly instrumental in completely de- 

 nuding the body of man. Certainly it is a fact that while we can 

 admire a European with a full and handsome development of hair 



